<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="utf-8">
</head>
<body>
	<canvas id="myCanvas" width="300" height="150" style="border:1px solid #d3d3d3;">
		Your browser does not support the HTML5 canvas tag.</canvas>

		<script type="text/javascript">

			var c=document.getElementById("myCanvas");
			var ctx=c.getContext("2d");
			ctx.strokeStyle="#0000ff";
			ctx.strokeRect(20,20,150,100);//画路径

		</script>
	</body>
	</html>